In the well known I.S. type of glassware forming machines, a number (generally from 8 to 16) of individual sections of the same construction are mounted side by side, and are arranged to operate out of phase with each other so that a substantially continuous flow of formed glassware is produced. Each section normally contains parison forming moulds and blow moulds, and may be constructed to receive 1,2,3 or 4 gobs of molten glass at a time into the corresponding number of parison moulds, in which the gobs are formed into parisons, which parisons are then transferred to the blow moulds and formed into the desired shape.
The gobs are supplied to the parison moulds through trough assemblies to which gobs are provided by a gob distributor. There is a trough assembly associated with each section, and the gob distributor is arranged to provide the required number of gobs to each trough assembly in turn through a number of scoops which are moved into alignment with upper end portions of the trough assembly.
Each trough assembly comprises, associated with each mould cavity of the section, an upwardly facing inclined trough, which carries a gob from the scoop into a position above and to one side of the parison mould, and a downwardly facing deflector which deflects a gob travelling down the trough into a vertical path to fall into the cavity of the parison mould.
It can be seen that, for each gob, a pathway is provided by the scoop, the upwardly facing trough and the downwardly facing deflector. It is essential to ensure that a gob arrives at the parison mould in its desired condition that this pathway is smooth, and does not comprise any changes of direction in a vertical plane. Consequently it is necessary to ensure that the three components are accurately aligned, in particular that, viewed in plan, there is no `dog leg` formed.
The alignment and orientation of the scoop is determined by the gob distributor.
The trough has an upper end portion which comprises two downwardly facing slotted lugs, which are fitted over a supporting rod which extends arcuately across the machine, and is located transversely on the rod by a locating block fixed to the rod and lying between the slotted lugs. A small amount of play length wise of the rod may occur, and the trough is free to move angularly about the rod.
A lower end portion of the trough is supported by a complex bracket which is supported by a hanger from a beam extending transversely across the machine. In general one hanger is provided for each section, irrespective of the number of cavities (i.e. number of troughs) in the section.
The deflector comprises an upper end portion which is supported by the aforementioned bracket, and a lower end portion which has a transverse lug with a vertical bore in it. This bore fits over a locating pin which is adjustable about x and y axes to enable adjustment of the position of the lower end portion of the deflector in relation to the associated mould cavity.
When it is necessary, in the operation of the machine, to adjust the position of the deflector, for example if there is a change of gob size, the position of the locating pin is adjusted to move the lower end portion of the deflector into the desired position. During operation of the machine it is in general not feasible to adjust the bracket which supports the upper end portion of the deflector and the lower end portion of the trough and consequently such adjustment of the deflector may cause the deflector and the trough to become misaligned into a `dogleg`, which can cause irregularities in the shape of the gob delivered to the mould and in its delivery time.
In U.S. Pat. No. 5,298,049 there is disclosed a trough assembly for the delivery of a gob of molten glass from a gob distributor to a parison mould cavity in a glassware forming machine comprising an upwardly facing inclined trough which is arranged to receive a gob from a scoop of the gob distributor and a downwardly facing deflector which deflects a gob which has travelled down the trough into a vertical path to fall into the parison mould cavity in which the deflector and the trough are mounted on a hanger which is supported in a frame member of the machine by a universal joint adjustable about three perpendicular axes. In this assembly adjustment of the position of the deflector may be made without causing misalignment of the deflector and the trough. However it suffers from a disadvantage in that the universal joint is expensive to manufacture.
It is an object of the present invention to provide a trough assembly of economical construction which allows for adjustment of the deflector and trough.